As a person raises their leg to take a step the knee comes in contact with the fabric of the trouser and the trouser fabric then rides up and over the knee creating friction. This friction in turn requires extra muscle energy to overcome the friction which results in an increased rate of muscle fatigue. In extreme cases, such as a stiff pair of rain pants, this friction can severely limit the wearer's range of motion. When a person is climbing, such as a ladder or a hill, or when squatting and standing, this effect and the resulting fatigue are significantly amplified.
There are other devices that have been developed to prevent the fabric in the knee portion of the trouser from getting stretched out in men's suits, such as U.S. Pat. No. 1,225,578 to Cieslik which discloses a detachable system worn on the inside of the trouser for raising the trouser leg when the wearer sits. However, this system actually relies on, and increases, friction across the knee to tension the belt and raise the trouser leg to prevent “bagging” of the knee. Likewise, U.S. Pat. No. 1,500,804 to Crawford discloses a non-removable set of straps attached to the posterior portion of the trouser leg which lifts the trouser leg when sitting. U.S. Pat. No. 1,173,139 to Abramson teaches a non-removable set of straps attached to the anterior portion of a trouser leg which likewise lifts the trouser leg when sitting.
Another method of raising the fabric of the trouser leg, Japanese patent application No. 2001-246805, discloses an elastic strap with a clip at one end for attaching to the trouser's belt, and a clip at the other end which is attached to the fabric of the trouser leg in the region of the knee. The tension of the elastic provides a continuous upward force which pulls the trouser leg up much like the effect you would achieve by grasping the fabric with your hand and pulling upward.
While providing a means for lifting the fabric of the trouser leg all prior methods had a number of disadvantages:                a. To prevent the fabric of the knee from becoming stretched the fabric is lifted by tensioning a strap against the wearer's leg at the cost of increased friction from the straps against the wearer's legs which results is increased muscle fatigue.        b. The cost of the strapping material and the cost of installing the strapping in the garment is significantly higher than the present invention.        c. The strapping material brings added weight to the trouser which has the effect of increasing fatigue since that added weight must be lifted by the leg each time the leg is raised.        d. The continual chaffing of the straps against the leg would be uncomfortable and annoying for anyone involved in active endeavors such as work or sports.        e. Elastic straps on the exterior of the garment present a safety hazard for work or sports as they can easily snag and lead to injury.        f. The tension of the elastic straps would continually vary depending on heat, moisture, wear and tear and other variables such that the performance would be inconsistent and require continual adjustment.        g. Having an elastic strap continually pulling upward can feel unnatural and uncomfortable when worn for long periods such as during work assignments.        
The present invention provides novel trousers and related methods of strain relief that overcomes the shortcomings of the previous inventions. Besides reducing stress on the body's muscular skeletal system, it also increases the wearer's range of movement in a safe and consistent manner. Several objects and advantages of the current invention are:                a. to reduce stress on the muscles and joints of a person's legs during physical activities such as walking, climbing, squatting and other repetitive movements in a manner that is comfortable to use.        b. to provide a method for reducing stress on the muscles and joints of a person's legs from repetitive movements in a manner that is consistently safe and will not pose a hazard due to snagging or spontaneously releasing under load.        c. to provide a method for reducing stress on the muscles and joints of a person's legs from repetitive movements in a manner that does not require continual adjustment by the wearer due to changing environmental conditions, or degradation of the support materials over time.        d. to provide a method for reducing stress on the muscles and joints of a person's legs in a manner that retains a consistent result throughout the lifespan of the garment.        e. to provide a method for reducing stress on the muscles and joints of a person's legs in a manner that will provide greater utility for the wearer due to it's convenience and ease of use.        f. to provide a method for reducing stress on the muscles and joints of a person's legs in a manner that is stylish and is more likely to be adopted and utilized because it does not impact the visual appeal of the garment.        g. to provide a method for reducing stress on the muscles and joints of a person's legs in a manner that does not increase the stress through added weight or friction.        
Further objects and advantages of the present invention are to provide a method of stress relief which is inherent to garments, which can be easily and inexpensively manufactured, which is light in weight, which is reliable and which requires no instruction or proficiency to use. Still further objects and advantages will become apparent from a consideration of the ensuing descriptions and drawings.